Although it is dominated by excrement, disease and garbage, the Wellcome Collection's latest show avoids the muddy thinking characteristic of many thematic exhibitions. Beautifully organised, it reveals the social, moral and scientific attitudes to dirt in different historical eras, from the homes of 17th-century Delft to a landfill site on modern-day Staten Island.

The head of the Cantone family, makers of pasta in Lecce, Puglia, is a proud man. He is a pillar of the community respected by all, and though he is about to retire there is a son to take over from him who, in the best of all possible worlds, looks likely to marry the beautiful girl who will provide the perfect match.

It’s not that often that the West End welcomes a genuinely new British musical, as opposed to an import or a revival. So it is refreshing to encounter this version of Erich Segal’s Seventies romance, originally a novella though best known as a film starring Ryan O’Neal and Ali MacGraw.

Presented earlier this year at Chichester, Love Story is the first West End show in more than two decades from versatile composer Howard Goodall.

Most British Grand Tourists of the 18th century, destined for Italy (there was an alternative Grand Tour of cultural capitals north of the Alps), followed a route from Paris to Turin and then on to Bologna, Florence, Rome and Naples, there turning to the far north-east for Venice as the last excitement before the journey home. In Turin, where the Court language of the day was French, they encountered the most modern city in Europe, its grid ground-plan embellished with churches, palaces and public buildings that were the last high kick of the Baroque. In Bologna they admired the serene post-Raphaelite paintings of the Carracci, Reni, Guercino and their followers. In Florence, where so many Englishmen gathered that they had no need to speak Italian, they came face to face with the Italian Renaissance and were utterly confused by it. In Siena they paused to take mistresses and learn Italian at last — two birds with one stone. In Rome, as they swooned before the wondrous relics of Antiquity — great ruins still half-buried, great sculptures sparkling clean, repaired and on view in the Vatican — I wonder if it occurred to them that they had experienced all this cultural education chronologically reversed and that they were as confused as we might be were we to absorb the history of art by first studying the sculpture of Gormley and Kapoor and the architecture of Foster and Rogers.

Why Niobe? A straw poll revealed that the title of Agostino Steffani’s work is not one that trips off the tongue of most opera buffs. And a trawl of the opera textbooks on my shelf suggested that while the composer was of some historical significance, Niobe was lucky to get more than a sentence.